1. Field
One or more embodiments described herein relate to a battery pack.
2. Description of the Related Art
A variety of devices are powered by batteries. Examples include mobile phones, digital cameras, laptop computers, and electric vehicles. The batteries may be incorporated into a battery pack equipped with a protective circuit for controlling charging and discharging operations.
The batteries in a battery pack may be charged by a constant current-constant voltage (CC-CV) charging method, in which CC charging is performed and then CV charging is performed. During CC charging, if the charging current and CC charging period are increased, the charging time period may be reduced. However, if charging is performed by charging current that exceeds a safe level, or if the battery is charged when the voltage of any of the batteries in the pack is equal to or greater than a predetermined voltage value, the battery pack may degrade at a more rapid rate. Thus, the charging device for the battery pack may determine whether a predetermined voltage value has been reached based on the magnitude of the voltage between the terminals of a battery pack.
However, the voltage between the terminals of the battery pack may be greater than the voltage of one or more of the batteries in the pack. In addition, the charging mode may be switched from the CC charging to the CV charging before the battery voltage reaches the predetermined voltage value. As a result, the charging time period may increase.